In order to package and dispatch sterile products, such as medical or surgical instruments or items, for example boxes or sachets containing syringes, it is known to use boxes that are made of cellular plastics material and treated in a sterilisation chamber together with the products that they contain. A known sterilisation treatment method involves filling the box with the not yet sterile product in question as it arrives from manufacturing, then subjecting the whole package to a sterilisation treatment using a suitable gas, such as EtO (ethylene oxide), in a sealed chamber. Following a predetermined exposure time of up to 75 hours, the gas is discharged from the chamber and is replaced with air before the product is removed from the chamber. The treated product is thus dispatched in its box without further handling before it arrives at its destination.
As the gas used for the sterilisation treatment is of a highly toxic nature as it has to eliminate all germs, provision is made to ensure no traces of gas remain trapped inside the packaging. The treatment procedures that are implemented are designed to provide complete safety with respect to the operators and persons responsible for handling the boxes, particularly when leaving the treatment chamber.
Plates of cellular plastics material are readily used for making the packaging boxes. This material is both light and resistant. It is comparable to corrugated cardboard in terms of mechanical performance and has the additional advantage of being durable and more resistant to contamination than said cardboard.
The term “plates made of cellular plastics material” denotes plates consisting of at least two flat parallel sheets that are separated from each other by partitions that are parallel to each other. The sheets and partitions provide longitudinal channels between them, which are called cells in the field. These plates are mainly obtained by extruding a plastics material, such as a polyolefin, through a rectilinear die having a suitable profile, which material is selected depending on the application intended for the material. Immediately downstream of the extrusion head, the material, which is still in the plastic state, passes between calibration plates in order to set the shape of the plate.
This type of plate is now commonly used and can act as a substitute for corrugated cardboard for certain applications, such as the aforementioned application. The common box is the American box. It comprises a strip with four panels each extended on either side by flaps that are folded at a right angle in order to form the base and the top or cover of the box.
The present applicant has developed a box that is used for sterilisation treatment, which box is protected by patent EP 1858760, in which the cover sheets forming the cellular plate are perforated with a plurality of holes to ensure that the gas circulates through said holes during the treatment phase inside the chamber.